Pressure indicator

ABSTRACT

A pressure indicator suitable for use with a device containing a fluid under pressure generally consisting of a movable means including a chamber communicable with the fluid under pressure, operable responsive to a predetermined pressure within the chamber for urging the movable means into a predetermined orientation, and biasing means cooperable with the movable means for urging the movable means out of the predetermined orientation when the pressure in the chamber is below the predetermined pressure.

United States Patent Gaskins [451 Aug. 1,1972

[54] PRESSURE INDICATOR [72] Inventor: Thomas Gaskins, Palmdale, Fla.

[22] Filed: Oct. 28, 1970 21 Appl. No.2 84,606

[52] Cl ..l16/34 R, 73/l46.8, 340/58 [51] Int. Cl ..B60c 23/06 [58]Field of Search ..73/l46.8, 146.3; 340/58; 1 16/34 R [56] ReferencesCited UNITED STATES PATENTS 1,28l,274 10/1918 Berry ..ll6/34R FOREIGNPATENTS OR APPLICATIONS 776,268 10/1934 France ..340/58 PrimaryExaminer-Donald O. Woodie] Attorney-Mason, Fenwick & Lawrence [57]ABSTRACT A pressure indicator suitable for use with a device containinga fluid under pressure generally consisting of a movable means includinga chamber communicable with the fluid under pressure, operableresponsive to a predetermined pressure within the chamber for urging themovable means into a predetermined orientation, and biasing meanscooperable with the movable means for urging the movable means out ofthe predetermined orientation when the pressure in the chamber is belowthe predetermined pressure.

3 Claims, 8 Drawing Figures PATENTEDMI: 1 I972 1N VENTOR THoMAs GA$KIN5ATTORNEYS PRESSURE INDICATOR This invention relates to a pressureindicator and more particular to a device for indicating when thepressure within a chamber has fallen below a predetermined value.

In the operation of conventional vehicles having pneumatic tires, anundue loss of pressure in the tires can result in undesirable tire wear,improper operation of the vehicle and unsafe driving conditions. Mostoften, it has been customary periodically to check tire pressures onlywhen a vehicle is being refueled or serviced, during which times thechecking of tire pressures either is overlooked or purposed deferred. Itthus has been found to be desirable to provide a device forautomatically indicating when the pressure of a pneumatic tire hasfallen below a predetermined amount.

Accordingly, it is the principal object of the present invention toprovide a novel pressure indicator.

Another object of the present invention is to provide a novel device forindicating when the pressure within a chamber has fallen below apredetermined amount.

A further object of the present invention is to provide a novel devicefor indicating the pressure in a pneumatic tire.

A still further object of the present invention is to provide a novelpressure indicator for a pneumatic tire which automatically will alertthe driver of a vehicle on which such indicators are installed that thepressure in the tires has fallen below a predetermined amount.

Another object of the present invention is to provide a novel pressureindicator which is simple in construction, inexpensive to manufactureand simple in operation.

Other objects and advantages of the present invention will become moreapparent to those persons having ordinary skill in the art to which theinvention pertains, from the following description taken in conjunctionwith the accompanying drawings wherein:

FIG. 1 is a front elevational view of an embodiment of the inventionmounted on a vehicle tire;

FIG. 2 is a side elevational view of the embodiment illustrated in FIG.1;

FIG. 3 is an enlarged cross sectional view taken along line 3,3 in FIG.1;

FIG. 4 is an enlarged cross sectional view taken along line 4,4 in FIG.3;

FIG. 5 is a cross sectional view similar to the view shown in FIG. 3,illustrating the embodiment in a different sequence of operation;

FIG. 6 is a perspective view of another embodiment of the invention;

FIG. 7 is a perspective view similar to the view as shown in FIG. 6,illustrating the embodiment in a different sequence of operation; and

FIG. 8 is an enlarged cross sectional view taken along line 8,8 in FIG.6.

Briefly described, the present invention relates to a pressure indicatorsuitable for use with a device containing a fluid under pressure, suchas a pneumatic tire for a vehicle, generally consisting of a movablemeans including a chamber communicable with the fluid under pressure,operable responsive to a predetermined pressure within the chamber forurging the movable means into a predetermined orientation, and biasingmeans cooperable with the movable means for urging the movable means outof the predetermined orientation when the pressure in the chamber isbelow the predetermined pressure. In one embodiment of the invention,the movable means comprises a flexible, inflatable enclosure meansdefining the chamber, and the biasing means comprises a rigid arm memberpivotally connected to a support member of the indicator and secured ata point spaced from the pivotal connection of the arm member, to theenclosure means, and a spring interconnecting the support member and thearm member. In another embodiment of the invention, the movable meanscomprises a flexible, inflatable enclosure means defining the chamber,and the biasing means comprises a spring member rigidly secured to asupport member of the indicator and secured to the enclosure means at apoint spaced from the support member.

Referring to FIGS. 1 through 5 of the drawings, there is illustrated afirst embodiment of the invention. The invention consists of a pressureindicator l0 mountable on the rim 11 of a wheel assembly 12, and whichcommunicates with the interior of an inflatable tire 13 mounted on therim 1 1 in the conventional manner. As best illustrated in FIG. 3, thepressure indicator includes a valve unit 14 mounted on the tire rim 11and indicator unit 15. The valve unit 14 consists of a mounting member16, a valve stem 17 and a conventional valve 18. The mounting unit 16essentially consists of a grommet having an enlarged end sectionengaging the inner side of tire rim section 11a, a reduced shank portion16b extending through an opening 11b in the rim wall section lla, anenlarged section 160 engaging the outer side of the rim wall section11a, and a threaded end portion 16d. The mounting member 16 preferablyconsists of a resilient material such as rubber which would readilypermit the insertion of the section 160 through the opening 11b, and thethreaded section 16d is formed of a rigid material which may consist ofany suitable metallic or plastic material.

The valve stem 17 includes a cylindrical section 17a providing an axialpassageway 17b and an integral offset section having a passageway 17dcommunicating with the passageway 1712. One end of the passageway 17b isthreaded so that the section 17a may be threaded onto the threaded endsection 16b of the mounting member with an enlarged end portion of thesection 17a enclosing the mounting section 160 and engaging the rim wallsection lla, as illustrated in FIG. 3. With the valve stem 17 threadedon the mounting member 16, the passageway 17b communicates with theinterior of the tire 13 by means of an axial passageway 16e provided inthe mounting member 16.

The valve 18 is disposed in the passageway 17b of the valve stem betweenthe outer end of the valve stem and the passageway 17d in the offsetsection 170 so that the passageway 17d will always communicate with theinten'or of the tire 13 through passageways 17b and 16e. The valve 18 isof the conventional type which will prevent leakage of air within thetire 13 through the valve unit, and which is operable in theconventional matter to supply air under pressure to the tire 13 throughthe valve unit. The indicator unit 15 consists of a mounting member 19,and elongated flexible enclosure member 20 and an arm member 21interconnecting the mounting member 19 and a free end of the enclosuremember 20. The mounting member 19 is provided with a reduced, threadedend section 19a threaded into a threaded opening in the end of theoffset section l7c, and a reduced opposite end section 19d onto whichthe inner end of the enclosure member 20 is secured. The mounting member19 is provided with a passageway 19c which is aligned with thepassageway 17d of offset section 17c when the threaded section 19a isdisposed in the threaded opening of the offset section as shown in FIG.3. v

The mounting member 19 is provided with-a projecting section 19d havinga pair of wall portions 19s and 19f which are disposed at right angles,as best illustrated in FIG. 4. The inner end of the arm member 21 ispivotally connected to the outer end of wall portion l9e by means of apivot pin 21a and is biased in a position substantially perpendicular tothe projecting section 19d by means of a spring 21b interconnecting theprojecting section 19b and the arm member 21, as best illustrated inFIG. 5. To accommodate the inner end of arm member 21 when it isdisposed in the position as illustrated in FIG. 5, the outer end of thewall portion 19f is provided with an opening 19g. As illustrated inFIGS. 3 and 5, the free end of the arm member 21 is secured to the freeend of the enclosure member 20 by means of a rivet 210.

When the arm member 21 is urged by the spring 21b into the position thatis illustrated in FIG. 5, the indicator member will engage an actuatingarm 22 of an electrical switch 23 mounted on the inner side of anadjacent fender of the vehicle, as best shown in FIGS. 1 and 2. Theelectrical switch 23 is provided with an elec trical supply circuit 25including an electrical supply source such as a battery 26, and an alarmdevice such as a light 27 so that when the indicator member 15 trips theactuating arm 22 to close the switch 23, the alarm device 27 will beenergized by the electrical circuit.

The components of the pressure indicator as described are designed sothat when air under pressure is supplied to the tire 13 through thevalve unit 14, and the tire 13 is under a predetermined pressure, theenclosure member will inflate and assume the orientation as illustratedin FIG. 3 with the arm member 21 disposed in substantial alignment withthe projecting section 19d. Under such circumstances, by viewing theposition of the indicator 15, the operator of the vehicle will be ableto know that there is sufficient pressure within the tire 13. Thecomponents of the pressure indicator further are designed, however, sothat when the pressure within the tire 13 falls below a predeterminedamount, the biasing action of the loaded spring 2lb will cause the armmember 21 to pivot about the pin 21a toward the position as illustratedin FIG. 5. When the arm member assumes the position as illustrated inFIG. 5, this will be an indication that the pressure within the tire 13has fallen to a critical level. Upon assuming the position asillustrated in FIG. 5, the indicator unit 15 will trip the switch 23thus energizing the alarm device 27 to warm the vehicle operator thatthe pressure level in the tires is critically low.

The construction of the pressure indicator as described, readily permitsthe inflation of the tire 13 with a conventional air supply lineavailable at most commercial service stations, which may be connected tothe free end of the valve unit 14 so that the valve 18 will be opened toadmit air from the pressure line into the tire 13 to the valve unit. Itfurther is to be noted that by a proper selection of materials anddesign of components, the pressure indicator will be calibrated so thatthe spring 21b will function to pivot the arm member 21 when thepressure in the interior of the tire 13 which communicates with theinterior of the enclosure member 20 through passageways 16e, 17b, 17d,and 170, falls below a predetermined level. When the vehicle operator isalerted to the low pressure in the tire 13, he will know to drive to thenearest service station and increase the pressure in the tires. Upondoing so, theincreased air pressure within the tire will again inflatethe enclosure member 20, causing the arm member 21 to pivot into theposition as illustrated in FIG. 3, and to reload the spring 21b.

FIGS. 6 through 8 illustrate another embodiment of the invention whichis similar in many respects to the embodiment illustrated in FIGS. 1through 5. The embodiment includes a valve unit 28 mounted on a wheelrim 29, and an indicator unit 30 which is mounted on the valve unit 28.As best illustrated in FIG. 8, the valve unit 28 includes a valve stemmember 29 having an offset mounting section 29a. The offset section 29ais provided with an internal passageway 29b which communicates with theinterior of a tire 31 through a passageway 29c of the valve stem member.

The indicator unit 30 consists of a mounting member 32 threaded into theouter end of the offset section 29a, an elongated flexible, enclosuremember 33 secured at one end to the mounting member 32 so that theinterior thereof communicates through a passageway 32a in the mountingmember 32, and passageways 29b and 290, with the interior of the tire31, and a spirally or helically shaped spring member 34 having the innerend thereof rigidly secured to the mounting member 32 and the outer endthereof secured to the end of the enclosure member 33 as at 35.

The embodiment as illustrated in FIGS. 6 through 8, functions similarlyto the embodiment illustrated in FIGS. 1 through 5 to indicate theamount of pressure within the tire 31. When air under pressure issupplied through the valve unit 28 to the tire 31, the enclosure member33 of the indicator unit will be caused to inflate and assume a positionor orientation as illustrated in FIG. 7. As the enclosure memberinflates, the spring member 34 is caused to expand and assume curvaturesof increased radii. As the air in the tire 31 begins to leak or isotherwise lost, and pressure within the tire 31 correspondinglydecreases, the indicator will be urged to the position or orientation asillustrated in FIG. 6, under the biasing influence of the spring member34. As soon as the indicator unit assumes the position as illustrated inFIG. 6, the vehicle operator would be alerted to the low level ofpressure within the tire.

It is contemplated that the indicator unit would be calibrated andappropriate markings placed on the enclosure member so as to indicatethe pressure within the tire 31. It further is contemplated that thetire pressures be indicated in increments from a point adjacent themounting member 32 and extending outwardly along the length thereof, andan end portion of the enclosure member be provided with a pointer orother indicator cooperating with the indicia on the inner end of theenclosure member to designate the'particular air pressure of the tire31.

Upon noticing the contracted configuration of the indicator unit 30 asillustrated in FIG. 8, the vehicle operator would be alerted of the lowpressure in the tire, and thus caused to drive immediately to thenearest service station to refill his tires. Upon doing so, theincreased pressure in the tire 31 will cause the enclosure member 30 tobecome inflated and subsequently assume the configuration as illustratedin FIG. 7 thus indicating that the proper air pressure in the tire hasbeen attained.

From the foregoing detailed description, it will be evident that thereare a number of changes, adaptations, and modifications of the presentinvention which come within the province of those skilled in the art.However, it is intended that all such variations not departing from thespirit of the invention be considered as within the scope thereof aslimited solely by the appended claims.

I claim:

1. In an inflatable tire having a valve including a valve stem providedwith a fluid passageway communicating with the interior of said tire, avalve seat provided in said passageway and a valve element engageablewith said valve seat, a device for indicating the pressure in said tirecomprising movable means including a chamber communicable with saidpassageway, operable responsive to a predetermined pressure within saidtire for urging said movable means into a predetermined orientation,said movable means comprising a flexible, inflatable enclosure meansdefining said chamber, secured to a base portion of said valve stem,

having a passageway intercommunicating said chamber and said firstmentioned passageway of said valve stem, biasing means cooperable withsaid movable means for urging said movable means out of saidpredetermined orientation when the pressure in said tire falls below apredetermined amount, said'biasing means comprising a rigid arm memberpivotally connected to said base portion and secured to said enclosuremeans at a point spaced from the pivotal connection thereof, and aspring interconnecting said base portion and said arm member.

2. In an inflatable tire having a valve including a valve stem providedwith a fluid passageway communicating with the interior of said tire, avalve seat provided in said passageway and a valve element engageablewith said valve seat, a device for indicating the pressure in said tireaccording to claim 1 wherein said base portion includes stops engageableby said arm member for limiting the travel of said arm member betweenpredetermined limits.

3. In an inflatable tire having a valve including a valve stem providedwith a fluid passageway communicating with the interior of said tire, avalve seat providedin said passageway and a valve element engageablewith said valve seat, a device for indicating the pressure of said tireaccording to claim 1 including an alarm system having means operableresponsive to a predetermined position of said arm member for actuatingsaid alarm system.

1. In an inflatable tire having a valve including a valve stem providedwith a fluid passageway communicating with the interior of said tire, avalve seat provided in said passageway and a valve element engageablewith said valve seat, a device for indicating the pressure in said tirecomprising movable means including a chamber communicable with saidpassageway, operable responsive to a predetermIned pressure within saidtire for urging said movable means into a predetermined orientation,said movable means comprising a flexible, inflatable enclosure meansdefining said chamber, secured to a base portion of said valve stem,having a passageway intercommunicating said chamber and said firstmentioned passageway of said valve stem, biasing means cooperable withsaid movable means for urging said movable means out of saidpredetermined orientation when the pressure in said tire falls below apredetermined amount, said biasing means comprising a rigid arm memberpivotally connected to said base portion and secured to said enclosuremeans at a point spaced from the pivotal connection thereof, and aspring interconnecting said base portion and said arm member.
 2. In aninflatable tire having a valve including a valve stem provided with afluid passageway communicating with the interior of said tire, a valveseat provided in said passageway and a valve element engageable withsaid valve seat, a device for indicating the pressure in said tireaccording to claim 1 wherein said base portion includes stops engageableby said arm member for limiting the travel of said arm member betweenpredetermined limits.
 3. In an inflatable tire having a valve includinga valve stem provided with a fluid passageway communicating with theinterior of said tire, a valve seat provided in said passageway and avalve element engageable with said valve seat, a device for indicatingthe pressure of said tire according to claim 1 including an alarm systemhaving means operable responsive to a predetermined position of said armmember for actuating said alarm system.